This invention relates to multiple spindle screw machines, and more particularly to an improved such machine which utilizes linear servo motors for effecting certain machine operations previously effected by camming mechanims. More particularly this invention relates to a multiple spindle screw machine of the type which is particularly suitable for operation by a computer.
Multiple spindle screw machines of the type described utilize a variety of attachments for effecting machining operations on pieces of bar stock that project from the work spindles carried by the rotatable spindle indexing head. Heretofore attachments of the type described, for example knurling, threading, cross drilling attachments and the like, have customarily been actuated by cam mechanisms of the type as shown for example in U.S. Pat. No. 3,323,398. Such mechanisms require a considerable amount of manual adjustment in order to effect the desired adjustments or changes in the attachments. In addition, the mechanical camming mechanisms and multiple gear drives of prior such machines have generated a considerable amount of vibration in the machine during its use, and such vibrations tend to interfere with the accuracy of the machine products. Also, considerable time is involved in adjusting the associated gear drive mechanism when it was desired to effect any changes in spindle speeds, thus causing a reduction in the productivity of the machinery.
It is an object of this invention, therefore, to provide an improved multiple spindle screw machine containing an improved spindle drive mechanism which is controlled electronically rather than by gears, thus enabling simple and instant changes in spindle speeds, when desired.
Another object of this invention is to provide a machine of the type described having improved operating mechanisms for the tooling attachments which are utilized for effecting various machining operations on the bar stock supported in the associated tool spindles.
Still a more specific object to this invention is to utilize servo motors for effecting actuation of the associated machine tool attachments and spindles of a machine of the type described, thereby permitting control of these operations by a computer.
In this connection still another object of this invention is to provide an improved multiple spindle screw machine which is operated by computer controlled linear servo motors, thus considerably reducing the down time heretofore experienced with prior art machines of the type which utlized cam operated mechanisms for such purposes.
Another object of this invention is to provide a machine of the type described in which the spindle supporting head and the spindle collet chucks are operated by a common servo motor.
It is an object also of this invention to provide for machines of the type described improved barrel chucking mechanisms for chucking work pieces in the respective machine spindles.
Still another object of this invention is to be provide improved, servo motor operated slide mechanisms for feeding bar stock into the respective spindles of machines of the type described.
Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with accompanying drawings.